US Tap Water Quality Database

An Environmental Working Group analysis of tap water tests from 1998 through 2003 for more than 39,000 communities nationwide shows that 260 pollutants were detected in the nation’s drinking water.

EWG collected tap water contaminant data from 42 states over a two and one half year period. The overwhelming majority of the data we obtained were from utilities, with a much smaller component from the states as a part of special monitoring initiatives. EWG painstakingly pieced these data together, and created a website where the public can access the information free of charge at www.ewg.org/tapwater.